ESS Topic 6.1 Intro to the Atmosphere - SL and HL (New Syllabus)

Atmosphere (6.1.1)

Layer of gases surrounding Earth that separates our planet from space and supports life.

Biosphere (6.1.1)

All living things and places where life exists on Earth; includes land, water, and air.

Differential heating (6.1.2)

Unequal warming of Earth's surface caused by differences in how sunlight hits different areas.

Tricellular model (6.1.2)

Pattern of three connected air circulation loops in each hemisphere that moves heat globally.

Troposphere (6.1.2)

Lowest layer of atmosphere where weather occurs; extends 16-17 km above Earth's surface.

Insolation (6.1.2)

Incoming energy from the Sun that reaches and warms Earth's surface and air.

Convergence (6.1.2)

Air movement toward centers of low pressure where air rises; opposite of divergence.

Divergence (6.1.2)

Air movement away from high pressure areas where air sinks; opposite of convergence.

Hadley cell (6.1.2)

Large air circulation loop between equator and subtropics that redistributes tropical heat northward/southward.

Ferrel cell (6.1.2)

Middle atmospheric circulation loop between subtropical and polar regions driven by neighboring cells.

Polar cell (6.1.2)

Smallest air circulation loop at high latitudes where cold air sinks and moves equatorward.

Greenhouse gases (6.1.3)

Atmospheric gases that trap and re-release heat energy from Earth's surface; includes CO₂ and methane.

Aerosols (6.1.3)

Tiny solid or liquid particles suspended in air that affect solar radiation and clouds.

Black carbon (6.1.3)

Dark soot particles from incomplete burning of fuels that absorb sunlight and warm the air.

Infrared radiation (6.1.3)

Long-wave heat energy released from Earth's surface after absorbing sunlight; also called long-wave radiation.

Radiative forcing (6.1.3)

Change in Earth's energy balance caused by factors like greenhouse gases or volcanic eruptions.

Greenhouse effect (6.1.4)

Natural warming process where gases trap outgoing heat, keeping Earth warm enough for life.

Enhanced greenhouse effect (6.1.4)

Extra warming from increased greenhouse gases released by human activities like burning fossil fuels.

Global warming (6.1.4)

Rising average temperatures worldwide caused by accumulation of greenhouse gases in the atmosphere.

Climate change (6.1.4)

Broad changes in Earth's weather patterns, temperatures, and ecosystems caused by global warming.

Dynamic system (6.1.5 HL only)

Continuously changing environment where components interact through physical and chemical processes; constantly adjusting.

Ozone layer (6.1.5 HL only)

Stratospheric region containing ozone molecules that protect life by filtering harmful ultraviolet radiation.

Altitude (6.1.6 HL only)

Height above Earth's surface; atmosphere becomes thinner as this measurement increases due to gravity.

Lapse rate (6.1.6 HL only)

Rate at which air temperature decreases with height; averages about one degree per 100 meters.

Milankovitch cycles (6.1.7 HL only)

Long-term changes in Earth's orbit and tilt causing climate variations over tens to hundreds of thousands of years.

Glaciation (6.1.7 HL only)

Period when ice sheets and glaciers expand due to cooling climate; opposite of interglacial.

Interglacial (6.1.7 HL only)

Warmer period between ice ages when glaciers retreat and temperatures rise; opposite of glaciation.

Quaternary period (6.1.8 HL only)

Geological time period starting 2.5 million years ago characterized by repeating ice ages and warm periods.

Anthropocene (6.1.8 HL only)

Proposed new geological epoch marked by significant human impact on Earth's systems and environment.

Albedo (6.1.8 HL only)

Measure of how much sunlight a surface reflects; ice has high values, dark surfaces low.

Photosynthesis (6.1.9 HL only)

Process where organisms use sunlight to convert carbon dioxide and water into oxygen and sugars.

Pre-biotic atmosphere (6.1.9 HL only)

Earth's ancient air before life evolved; contained very different gas mixtures than today's atmosphere.